Cutting-tool for sound-recording machines.



A. N. PETIT, DECD.

A. 0. PETlT, ADMINISTRATOR. GUTUNG TOOL FOR SOUND RECORDINGMACHWES.APPLICATION FILED FEB. 12. 1914. RENEWED APR. 14.1911.

1 246,652. Patented Noy. .13, 1917.

Inventor Witnesses aZe MN/2" an i dlg flfegifgilr zffiam 429w Jaw %%baomA tlorneyf UNITED STATES PATENT @FFICE.

ADEMOB N. PETIT, F ORANGE, NEW JERSEY; ALBERT O. PETIT, ADMINISTRATOR 0FSAID ADEMOR N. YETIT, DECEASED, ASSIGNOR To JOHN L. LOTSCH, TRUSTEE, 0F

BROOKLYN, NEW YORK Specification of Letters Patent.

Patented Nov. 13, 1917.

Application filed February 12, 1914, Serial No. 818,350. Renewed April14, 1917. Serial No. 162,143.

To all whom it may concern:

Be it known that I, ADEMOR N. Pn'rrr, a citizen of the United States,residin at Orange, county of Essex, and State of ew Jersey, haveinvented a certain new and useful Improvement in Cutting-Tools forSound-Recording Machines, of which the following is a specification.

My invention relates to tools for cuttin the record grooves records ofthe latera type wherein a sinuous groove of substantially uniform depthis cut into a disk or tablet rotated beneath and in engagement with acutting tool which is held stationary relatively to the rotativemovement of the disk or tablet, and which moves laterally with respectto the motion of the disk so that a spiral groove may be cut in thesurface of the disk- When the cutting tool is properly attached to thediaphragm of a sound recording machine and said diaphragm is vibrated,the cutting tool is moved laterally by the sound waves and a sinuousgroove is cut, and this sinuous groove is disposed in a spiral or helixon the surface of the disk or tablet.

In all previous cut or traced records the groove has been made of Vshape, U shape, semi-elliptic shape, semi-circular arc shape,

or with a flat or rounded bottom having diverging walls. All of theseforms are alike in one respect, the walls adjoin the record surface at asharp angle to the latter and produce a thin, sharp, fragile, edge which85 cannot be made smooth, as is highly desirable in a talking machinerecord, and which edge from the nature of the material used in themanufacture of such articles, will be very quickly broken off, therebyexciting false vibrations in the reproducing stylus and diaphragm andproducing discordant sound vibrations.

The object of my invention is to provide a cutting tool for shapinggrooves suitable for use in talking machine records and to so proportionand form the tool that the resulting record groove will be of such ashape that all sharp, thin edges will be eliminated and a smooth curvedwall from the bottom of the groove up to and merging into the surface ofthe record, will be secured. The form of record roove produced by theuse of my improvef cutting tool is not claimed herein, but is made thesubject of a separate application filed on even date herewith.

This and further objects will more fully appear from the followingspecification and the accompanying drawings taken together orseparately.

In the drawings:

Figure 1 is a sectional view of a portion of a recording machine,showing a cutting tool in operative connection therewith.

Fig.2 is a sectional view of the same, taken at right angles to Fig. 1.

Fig. 3 is a greatly enlarged sectional view of the preferred form ofcutter.

Fig. 4 is a side view of the cutting tool.

Fig. 5 is a side view of the stock from which the tool is produced.

Figs. 6, 7, 8 and 9 are front views of modified forms of cutters.

In all of the above views corresponding parts are designated by the samereference characters. v

A suitable blank disk or tablet 11 made of any well-known or preferredmaterial is carried on a turntable 12 which is mounted on the shaft 13of a motor suitable to rotate the blank and cause relative lateralmovement of the blank and a cutting tool 14 which may be suitablyconnected to an ordinary recording diaphragm so that it will be given asidewise motion by the vibrations of the diaphragm while the blank isrevolving beneath it and it is being fed laterally across the face ofthe blank.

The preferred embodiment of my preferred cutting tool is shown in Figs.3 and i. 15 represents a cylindrical body having one end turned down tonipple form, that is, having an axial projection with a rounded apex 16and flaring sides 17 which merge into the end of the cylinder by meansof a curve 18. A portion of the cylinder is cut away at one side to apoint a short distance beyond the medial line, as shown by the dottedline in Fig. 5. By cutting away the stock as described a tool of theshape shown in Figs. 3 and i will-be produced, and such a tool will cuta groove of the same shape as the nipple shaped projection.

It is obvious that various modifications may be made without departingfrom the spirit or scope of my invention.

It is to be understood that I do not limit myself to a disk record andit is obvious that the invention herein described and disclosed isequally applicable to the cylindrical and other types of record.

In accordance with the provisions of the patent statutes I have nowdescribed my invention together with the apparatus which I consider torepresent the best embodiment thereof, but I desire it to be understoodthat the apparatus is merely illustrative and that the invention is notto be understood to be so limited, and that the invention can be carriedout in other Ways.

Having now described my invention, what I claim and desire to secure byLetters Patent is:

1. A cutting tool for sound recording machines having a cutting edgewhich merges into a line on the plane of the surface to be acted on.

2. A cutting tool for sound recording machines having its cutting edgesmerging into a line on the plane of the surface to be acted on.

3. A cutting tool for sound recording machines having divergin edges,said edges merging into a line on t e plane of the surface to be actedon.

4. A cutting tool for sound recording machines having a roundedextremity and rea ers edges merging into a line on the plane of thesurface to be acted on.

5. A cutting tool for sound recordin machines having a roundedextremity, an flaring edges, sald edges merging into a line on the planeof the surface to be acted on.

6. A cutting tool for sound recording machines having cutting edgesWhich are rounded into a line on the plane of the surface to be actedon.

7 A cutting toolfor soundrecording machines having diverging edges, saidedges being rounded into a line on the plane of the surface to be actedon.

8. A cutting tool for sound recording machines having a roundedextremity and sides rounded into a line on the plane of the surface tobe acted on.

9. A cutting tool for sound recording machines having a roundedextremity, and flaring sides, said sides being rounded into a line onthe plane of the surface to be acted on.

This specification signed and witnessed this 11th day of February,1914;.

ADEMOR N. PETIT.

Witneses:

JoHN L. LOTSCH, ELIJAH F. MUNN, Jr.

